1. Field of the Invention
The present invention relates to a device, system, method, and program for selecting a motion of an operational object suitable to a condition according to a motion of a person. More particularly, the present invention relates to a device, system, method, and program to enable an avatar to dance in a virtual world according to a choreographed data.
2. Description of Related Art
People can express themselves or communicate with other people through operational objects such as robots and avatars in a virtual world. For example, a person can cause an avatar, which is his or her own operational object, also called a character representing the person, in a virtual world, to dance according to a choreography by operating the avatar in order to express himself or herself or communicate with other people. Moreover, a person can feel as if he or she actually danced, by causing his or her avatar to dance according to a choreography. There are several conventional techniques for causing an operational object to dance according to a choreography. The following presents some examples of such conventional techniques.
Japanese Patent Application Publication No. 2001-276291 discloses a dance game system with which a player can play a dance game by using choreography data previously created by the player. This dance game system composes a choreography based on dance steps that the player performs to music on a foot stepper provided to the dance game system, and then registers the choreography in the dance game system. In addition to choreographies prestored in the dance game system, choreographies thus registered in the dance game system can be used for dance games.
Japanese Patent Application Publication No. 2002-042168 discloses a dancing image exaggerating and synthesizing apparatus for causing a virtual dancer of a three-dimensional computer graphics (3DCG) to perform a highly-sophisticated dance by exaggerating a dance of a person who dances to music. The dancing image exaggerating and synthesizing apparatus synthesizes a dancing image of an actual person and dance patterns read from previously-prepared dance patterns. The dancing image is obtained by composing an image of the person dancing to accompanying music with a camera, and the read dance patters are those keeping pace with the tempo of the accompanying music. In this way, the dancing image exaggerating and synthesizing apparatus generates an image in which a 3DCG virtual dancer is performing the dance.
Japanese Patent Application Publication No. 2005-297095 discloses a robot apparatus that imitates observed motions of a user and also performs new motions obtained by modulating the motions of the user. The robot apparatus captures an image of motions of a user from a camera, and performs the motions. In addition, the robot apparatus accumulates the captured motions of the user in a storage unit inside the robot apparatus, and creates and performs new motions based on the accumulated motions of the user.
The system according to Patent Document 1 provides a variation in the motions of an avatar, which is an operational object, by changing a combination of steps. However, different motions cannot be selected and assigned to steps on each position which limits the variation of selectable motions. In addition, since motions of a user are not directly reflected in motions of an operational object, the user cannot feel a union with the operational object. On the other hand, the techniques described in Patent Documents 2 and 3 are capable of reflecting motions of a user directly in motions of an operational object, but have a drawback in that some undesired motions are also directly reflected against the wishes of the user. Moreover, easy and simple implementation of these techniques is impeded by the inconvenience of a user having to install multiple cameras and dedicated devices.